The present invention relates generally to round balers with net-wrapping capabilities, and more particularly to a net wrapping mechanism for a round baler that self-threads a new roll of wrapping material as the initial roll is consumed.
In the crop packaging industry, generally a smaller part of the cattle/dairy industry, round balers have become quite prevalent for their capability of producing a conveniently sized cylindrical bale, very often automatically wrapped with a sheeting material such as net or film. Prior art round balers generally have a bale-forming chamber defined by an apron comprising an array of side-by-side belts, transverse slats trained on chains, a plurality of rolls or a combination of these various elements, e.g., rolls and belts. Crop material, such as hay, is picked up from the ground as the baler travels across the field, and is fed into a fixed or expandable chamber where it is rolled up to form a compact cylindrical hay package. While still inside the bale-forming chamber in its compacted form, the outer surface of the package is wrapped with twine or other wrapping material, such as film or net, prior to ejection of the wrapped bale from the chamber onto the ground for subsequent handling. The wrapping mechanisms generally dispense wrapping material from a roll, and have a location for a stored roll, but in order to use the stored roll, the operator must stop the machine and manually load and thread the second roll.
Common practice has the baler wrap the bales with twine, net-like or continuous plastic sheeting. With twine, the bale is wrapped back and forth from side-to-side as the bale is turned, from a single dispensing mechanism, or back and forth from middle-to-side as the bale is turned, from dual dispensing mechanisms with twine numerous time, the twine “gripping” the crop material and prior wrappings of twine adequately to hold the package together in a process often referred to as “tying”. Net wrap is made of a an extruded polymer with the appearance of a fish net, generally equal in width to the bale being formed, with regular openings therethrough and is overlapped on itself to hold the package together. An adhesive may be used to improve the holding power of the net wrap. Plastic wrap, or film, is a generally continuous sheet of plastic, also generally the width of the bale being formed, with a somewhat adhesive surface that grips itself when overlapped and the crop material to form the package.
Replacing a sheet roll on current round balers generally requires a substantial amount of work. First, the operator must remove the empty roll and carry a full roll from the storage box to the wrapper assembly in the front of the baler. After installing the full roll into the wrapper assembly, the operator must thread the end of the roll around spreader rolls and through the duckbill, or similar, assembly. The process takes an experienced operator about five minutes, and would be done once or twice during a normal baling day. While this amount of time is small, any improvements made to this reloading cycle will help reduce operator fatigue and stress, and as such will offer significant marketing advantage over competitive units.
It would be a great advantage to provide a self-threading capability to a round baler wrapping mechanism that overcomes the above-identified problems and disadvantages.